Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale

Peters, Wouter ; van der Velde, Ivar R. ; van Schaik, Erik ; Miller, John B. ; Ciais, Philippe ; Duarte, Henrique F. ; van der Laan-Luijkx, Ingrid T. ; van der Molen, Michiel K. ; Scholze, Marko LU and Schaefer, Kevin , et al. (2018) In Nature Geoscience 11(10). p.744-748
Abstract

Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of... (More)

Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001–2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon–climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response.

(Less)
Please use this url to cite or link to this publication:
@article{16095897-779f-452a-a183-1ecc6f3814ad,
  abstract     = {<p>Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO<sub>2</sub> growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the <sup>13</sup>C/<sup>12</sup>C stable isotope ratio in atmospheric CO<sub>2</sub> to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001–2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon–climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response.</p>},
  author       = {Peters, Wouter and van der Velde, Ivar R. and van Schaik, Erik and Miller, John B. and Ciais, Philippe and Duarte, Henrique F. and van der Laan-Luijkx, Ingrid T. and van der Molen, Michiel K. and Scholze, Marko and Schaefer, Kevin and Vidale, Pier Luigi and Verhoef, Anne and Wårlind, David and Zhu, Dan and Tans, Pieter P. and Vaughn, Bruce and White, James W.C.},
  issn         = {1752-0894},
  language     = {eng},
  number       = {10},
  pages        = {744--748},
  publisher    = {Nature Publishing Group},
  series       = {Nature Geoscience},
  title        = {Increased water-use efficiency and reduced CO<sub>2</sub> uptake by plants during droughts at a continental scale},
  url          = {http://dx.doi.org/10.1038/s41561-018-0212-7},
  doi          = {10.1038/s41561-018-0212-7},
  volume       = {11},
  year         = {2018},
}